桥梁方案比选和设计毕业设计.doc

摘 要 本设计是根据设计任务书的要求和《公路桥规》的规定,对位于昆山，连接到312国道上的一座桥梁进行方案比选和设计的。对该桥的设计，本着“安全、经济、美观、实用”的八字原则，本设计提出三种不同的桥型方案进行比较和选择：方案一为预应力混凝土连续梁桥，方案二为预应力混凝土组合梁桥，方案三为梁拱组合桥。经由以上的八字原则以及设计施工等多方面考虑，比较确定预应力混凝土组合梁桥为推荐方案。 在设计中，桥梁上部结构的计算着重分析了桥梁在使用工程中恒载以及活载的作用力，采用整体的体积以及自重系数，荷载集度进行恒载内力的计算。运用杠杆原理法、G-M法求出活载横向分布系数。进行了钢束的布置，估算了钢绞线的各种预应力损失，并进行预应力阶段和使用阶段主梁截面的强度和变形验算，挠度的计算。由于桥址附近地势较高，且地下土层的地质情况较差，所以下部结构采用桩基础，采用板式橡胶支座，还采用了U型桥台，并分别对桩基础、板式橡胶支座和U型桥台进行了计算和验算。 本设计全部设计图纸采用AutoCAD 2004辅助设计绘制并打印出图，计算书采用word编档、排版，打印出设计。 关键词： 预应力混凝土、荷载、横向分布系数、钢束、应力验算Abstract Located in Kunshan, connected to a bridge on national highway 312 for scheme selection and design, according to designing assignment and the standard of road and bridge. For the purpose of make the type of the bridge corresponding with the ambience and cost saving, this paper provides three different types of bridge for selection: the first one is Prestressed concrete continuous beam bridge; the second one is Prestressed Concrete Girder Bridge.; the third one is Beam Arch Bridge..After the comparisons of economy, appearance, characteristic under the strength and effect, the second one is selected. In the design, the checking calculation of the bridge superstructure in the focused analyzed the action of dead load and live load in using statement, adopting the overall volume and the weight factor, and load set degree of internal forces of the dead load calculation. Using lever principle , G-M method calculated transverse distribution coefficient of live load factor. The arrangement of the steel beam, the various estimates of the loss of prestress steel strand, and prestressed stage and the stage of the main beam with the strength and deformation checking, and deflection calculations. For higher ground near the bridge site, and the geological conditions underground soil is poor, so the lower part of the structure with pile foundation, the use of laminated rubber bearings, also using U-abutment, and pile foundation, respectively, laminated rubber bearin